The process of inoculating one day old chicks and other fowl has become fairly commonplace in the commercial hatchery industry. One person with an automated vaccinator can inoculate thousands of chicks per day. Such devices are described in, U.S. Pat. Nos. 4,863,443 to Hornung, 4,515,590 to Daniel, 4,177,810 to Gourlandt and 4,108,176 to Walden.
The inoculation process involves placing one chick at a time on a known injection device, which detects the chick and cycles through its injection procedures. The chick, presumably inoculated, is then released by the operator, slides off the injection device and falls into a container for the inoculated chicks. This procedure is repeated for a preselected number of chicks, usually a run of one hundred, at which point the injection device notifies the operator with a sound alarm. The operator then replaces the now-filled container of inoculated chicks with an empty container and begins a new run.
The prior art inoculation devices usually comprise a single, outer housing within which is contained all necessary mechanical and electrical components of the inoculation system. The housing usually includes an inclined work surface on which the chick to be injected is placed, the surface having an aperture through which a syringe needle reciprocrates to inject the chick, a syringe mounted on the opposite side of the work plane for urging vaccine through the needle when the needle penetrates the chick and a switch and switch housing mounted on the work surface adjacent the aperture.
However, the known devices are not entirely satisfactory. With the prior art chick switch housings it is difficult to ensure that each chick is aligned correctly with regard to the syringe needle when the operators use their fast hand movements during the inoculation procedures. An improperly located injection can result in an inadequate inoculation, injury or even death to the chick. In addition, due to the repetition and haste with which the operator handles the chicks, it is common for chicks to be placed near the switch housing without actuating the switch and without causing the system to cycle. Thus, an undesirable percentage of uninoculated chicks are mixed in the container with inoculated chicks.
In addition, because the environment in commercial hatcheries is far from clean and because of the repetitive contact between the chicks and the switch, it is common for the switch housing to become clogged with feathers, etc. It then becomes necessary to halt the inoculation process in order to clean or replace the switch, thus resulting in down time and fewer inoculated chicks per day.
The outer housing of the prior art inoculators also requires frequent cleaning; however, a quick, liquid washdown is not possible because of the proximity of water-sensitive components contained within the housing.
It is also common for the compartment within the housing to become contaminated with feathers, dirt and other matter. In order to clean the compartment, it is sometimes necessary to remove from the housing some of the working components of the system and clean the compartment by hand or with a compressed air blower, resulting in further down time and less productivity.
The productivity of each operator is further reduced because of the number of hours the operator must spend at the end of each day cleaning and sterilizing the syringe and supply conduits contaminated by the vaccine.
With the known injection devices, an additional spray apparatus can be separately attached to the injection device for spraying vaccine to the eyes of the chicks as the chicks are inoculated. The known spray attachments require a separate compressed air signal in order to drive the topical spray.